The true benefit of rational numbers is realised once there is support for bigints. Jürgen has suggested that that is planned, and personally I can't wait.
Regards, Elias On 29 August 2017 at 08:59, Frederick Pitts <fred.pit...@comcast.net> wrote: > Louis, > > Thanks for the quick response. > > After working with the technique a bit, I observe that as long > as the rational number denominator is well within the range of integers > representable by floating numbers, 1 ∧ n returns the correct result. > But if the absolute value of the denominator exceeds 2 ⋆ 35, the > technique returns incorrect results. For instance, > > fiMax ← × / 53 ⍴ 2 ⍝ largest integer 53-bit f.p. mantissa holds > fiMax > ╔════════════════╗ > ║9007199254740992║ > ╚════════════════╝ > 1 ∧ fiMax ⍝ Correct result for fiMax > ╔════════════════╗ > ║9007199254740992║ > ╚════════════════╝ > 1 ∧ ÷ fiMax ⍝ Incorrect result. 1 is numerator of reciprocal. > ╔═╗ > ║0║ > ╚═╝ > > I was hoping to be able to access correct rational number parts > even when they approach the ⎕SYL[20;2] limit of 9200000000000000000. > It seems a shame to loose so much of the integer range because floating > point operations are sneaking into the numerator and denominator access > methods. > > Regards, > > Fred > > On Tue, 2017-08-29 at 00:08 +0200, Louis de Forcrand wrote: > > Hi, > > > > No APL kb with me right now, sorry :( > > > > 1 LCM n > > > > gives the numerator of a fraction (floating or exact). If you need > > the denominator, do the same with the inverse of n. If you need both, > > for example: > > > > 1 LCM n POW 1 _1 > > > > Cheers, > > Louis > > > > > On 28 Aug 2017, at 23:24, Frederick Pitts <fred.pit...@comcast.net> > > > wrote: > > > > > > Hello, > > > > > > Is there an existing mechanism for accessing rational number > > > numerator and denominator parts analogous to that for accessing > > > complex > > > number real and imaginary parts? If yes, please let me know > > > how. If > > > no, can a mechanism be implemented? > > > > > > Respectfully, > > > > > > Fred > > > > > > > > >
